Drill-chuck



C. L. RUSSELL.

DRILL CHUCK.

APPLICATION FILED DEC. 6. 1918.

Patented Aug. 31,1920

[120612 for:

warren sra'rssra' rrsr orric'sf cHAnLEs iivonnussntn, or i nw'yoitmj v. Y.

DRILL-CHUCK.

T 0 all whom itmayconcern: N v

7 Be it known that I, GHAiiLn'sLYoN RUS- SELL, a citizen of the United States of America, residing at the city of New York, in the county of Bronx, State of New York, have invented certain new and useful Improvements in Drill-Chucks, of which the annexed-isa specification, reference being had to the accompanying drawings.

This invention relates more particularly to automatic drill chucks, and has for an object to provide in such a chuck of the rolling jaw type, a wide range of jaw opening,

a strong gripping action anda form of jaw affording many manufacturing advantages. In the drawings accompanying this specification one practicable embodiment of my invention is shown by way of illustration, wherein:

F igure 1 is a s de elevatiom partly 'in central section of my improved-chuck- Fig. 2 is an elevation of the body port on which carries the jaws.v

Fig. 3 is a cross sectional view,taken at about the plane of the l ne 3-3 of Fig. 1.

Fig. 4 is a similar cross sectional view,

showing the jaws in their closed position.

Fig. 5 is a cross sectional view, taken on a plane at about the line 55 of Fig. 1.

Fig. 6 is an enlarged fragment of the showing of Fig. 4, and

Fig. 7 is a perspective view of one of the jaws removed from chuck. i The body portion 8 of the chuck, illustrated in elevation in Fig. 2, is that portion which may be regarded as carrying the jaws and which is adapted to be connected to the rotary driving spindle in some suitable manner, preferably by a taper seat, illustrated by the dotted lines 9. This, present chuck is an improvement on that style of chuck, wherein cylindrical jaws are forced inwardly by means of cams and into position to engage the drill spindle, whereupon the combined action of the parts effects a rolling motion of the jaws and forces'them by a rolling motion farther up on the cam surfaces and consequently inwardly and against the drill shank. In the present instance there are shown three jaws 10,.each' of these jaws being a segment of a cylinder, preferably a truncated cylinder wherein the bases are of substantially equal area. In the manufacture of these jaws an easy procedure is to turn up the cylinders or rather a Specification of Letters Patent; Patengted A110. 31, 1920. if Application filed December 6,'1918. Seria1 1104265 29. i v

long bar into the proper cylindrical shape and slab ofl the sides 11. By this, means, I

the curved portions 12 will be true cylinders and theportion of the rolling face 12, ad acentthe sidell, willremain intact, which condition wouldbe hard to accomplish if a fiat-bar were placed in agrinding machine and its edges ground to cylindrical form.

The side walls of the slots are preferably so located that a plane midway between them i is disposed substantially radially of the head 8. These side walls17 are located a sufficient distance apart'in relation to the thickness of the rollers, that is theYdistance v .70 A cam 15 is provided .for each jaw. :The

head is provided with a slot 16 for each'jaw..

apart of the facesll, that the, jawsfmay have a rocking movement ina'the slots. Some holding the jaws in their initial or idle position. In the present illustration the jaw is shown carrying at the top and bottom of each side, a spring finger 18. The fingers on the forward side being directed inwardly and engaging the side of the slot toward the center of the head, and those on the rear side engaging the outer edge of the slot, thereby normally holding the j aws in a position opposite to that shown in Fig. 6. To

enable the spring fingers to escape crushing, suitable recesses 19 are provided in the aws for receiving these fingers when depressed.

In the operation of this form of automatic drill chuck, the jaws are normally held at their extreme inward or closed position. This is usually effected by spring means. In the present illustration, coiled 5 clock spring 20 is shown connected to the head 8 and to the sleeve 13, in such manner that these parts are rotated one relatively '80 convenient means may be employed for to the other and into such a position that the jaws normally occupy a position at the crests 21 of the cams. When it is desired to insert a tool spindle into the center bore of the head and through the opening 22 in the sleeve, the operator grasps the chuck, which is assumed to be rotating, that is he grasps the sleeve 13 and permits it to slide fric- I with a full cylinder.

'jaws will be pressed outwardly a sufficient amount to receive the tool shank and may, if desired, be pushed outwardly to the full extent of their outward movement and until they engage' thelow portion 24 of the cams. 7

In the Fig. 3 position, it will be seen that owing to the slabbing off of the sides of the cylindrical jaw, the jaw has a greater am 'plitude of movement across the face of the cam and consequently a greater movement radially of the chuck body than is possible Upon the operator releasing the sleeve 13 to the action of the spring 20, the relative movement of the body 8 and sleeve 13. with the cams 14, causes the jaws to move inwardly until they engage the tool shank 28. The jaws slide upon the cams as they are carried forwardly thereon, and as soon as the inward rounded edges of the jaws are pressed against the tool shank, by their inward movement, a rolling motion given the jaws and they roll against the tool shank and roll forwardly on the cam, therebyincreasing the grip upon the tool shank in excess of the bite which is effected by an inward radialmovement of the jaw unaccompanied by this rolling movement. Owing to the fact that there is .a true rolling motion between the jaw and the cam, and the jaw and the tool shank, none of the three parts named is injured or marred by the strong clamplng engagement afforded.

Although but one illustrative embodiment of the invention'has been shown and described, it will be apparent that changes will be made within the scope of the claims without departing from the spirit of my 7 invention.

What I claim as my invention is 1. In a chuck, the combination with a sleeve, of a jaw carrier mounted in and rotatable' relatively to said sleeve, the jaw carrier having a centrally disposed tool seat and jaw pockets extending outwardly from such tool seat, and a substantially fiat jaw in each such pocket having a rounded tool engaging face at its inner edge and'a rounded cam engaging face at its outer edge, the r the cam andisalso capable of a limited rolling movement against the cam and against the tool when the said rounded edge faces are engaged by these.

2. A chuck as set forth in claimrl wherein the rounded edges of the jaw are substantially cylindrical segments having a common'axis. V r

In testimony whereof I afiix my signature this 27th day of November, 1918.

CHARLES LYON RUSSELL. 

